SEATTLE -- February 14, 2004 -- The Consortium of Multiple Sclerosis Centers (CMSC) announced today that the presence of neutralizing antibodies (NAbs) has a significant effect on interferon beta therapy and this issue warrants the attention of health care providers and patients with multiple sclerosis (MS).

The findings, presented at the American Association for the Advancement of Science (AAAS) and National Association of Science Writers (NASW) annual meeting, state that when an MS patient develops NAbs, his/her body perceives these protein-based therapies to be "foreign," like an allergen or infection causing organism and mounts an immune response against them, basically rendering the therapy less effective.

According to Andrew R. Pachner, M.D., Professor, Department of Neurology and Neurosciences at the University of Medicine and Dentistry of New Jersey Medical School, "Patients who develop NAbs show higher relapse rates, an increased number of enlarging brain lesions, and new lesion formation compared with NAb-negative patients."

Long-Term MS Therapy and Neutralizing Antibodies

The rise of biologics (protein-based medications, which are similar to regulatory proteins normally produced by humans and generally administered by injection or infusion) has benefited countless patients in the treatment and management of chronic diseases, including cancer, anemia, diabetes, rheumatoid arthritis, psoriasis and MS.

"Biologic therapies are a significant advancement in the treatment of chronic, relapsing diseases, but in recent years, we have observed an unexpected consequence of attacking the immune system," said Frederick Munschauer, M.D., Chair, Department of Neurology, SUNY at Buffalo School of Medicine and Secretary of the Board of Governors, CMSC, and the Co-Chair of the CMSC Cooperative Studies Group in Multiple Sclerosis.

Relapsing-remitting MS patients take disease-modifying therapies called interferon betas, which reduce the frequency and severity of MS relapses or attacks, reduce brain lesion development and generally delay future disability. Few options for treating MS existed until these biologic therapies became available. However, some MS patients taking an interferon beta (Avonex®, Betaseron® or Rebif®) develop neutralizing antibodies (NAbs), which limit or prevent the medication from having its full therapeutic effect. As treatment with biologics increases, physicians and patients need expert guidance regarding this issue.

In November 2003, a CMSC consensus statement on how biologics affect NAbs was published in Neurology. The consensus was the result of an extensive review of studies by over 33 immunologists and neurologists. The CMSC sought to answer the following questions:

What is currently known about anti-interferon beta antibodies and their effects on patients with MS treated with interferons?

Do all interferon betas result in comparable levels of NAbs?

What are the tests available to detect antibodies; how accurate are they; and what is the best method for their detection in clinical care?

What are the research priorities in advancing our knowledge of this field?

Current and Future Strategies

The CMSC recommends that a laboratory test for NAbs be performed routinely with other standardized tests at least one and two years after start of treatment. Additionally, the CMSC counsels patients and their doctors to consider NAbs when selecting a long-term treatment for MS. Based on prescribing information, NAbs have been detected at different levels among the available interferon betas:

43% of Betaseron patients (Interferon Beta-1b)

24% of Rebif patients (Interferon Beta-1a)

5% of Avonex patients (Interferon Beta-1a)

"Therefore, it is incumbent on both physicians and their patients to understand the potential effects of NAbs on the long-term treatment for MS," urged Frederick Munschauer, M.D. "As new information becomes available, this should be factored into the patient's care. For now, selection of MS therapy should be based on how effective the treatment is over the long-term in light of the potential impact NAbs can have among these therapies. Currently, if a patient develops NAbs, physicians are forced to consider a more toxic or less effective agent."

What is multiple sclerosis?

Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system (CNS). The CNS consists of the brain, spinal cord, and the optic nerves. Surrounding and protecting the nerve fibers of the CNS is a fatty tissue called myelin, which helps nerve fibers conduct electrical impulses. Myelin not only protects nerve fibers but also makes their job possible.

In MS, myelin is destroyed in multiple areas, leaving scar tissue. These damaged areas are also known as plaques or lesions, and sometimes the nerve fiber itself is damaged or broken.
When myelin or the nerve fiber is destroyed or damaged, the ability of the nerves to conduct electrical impulses to and from the brain is impaired or disrupted, and this produces the various symptoms of MS, such as vision problems, numbness, loss of balance, difficulty walking and paralysis.

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About the CMSC

Founded in 1986, the CMSC is a multi-disciplinary organization providing a team approach to MS care. The organization has over 200 member centers in the U.S., Canada, and Europe and represents over 4,000 health care professionals worldwide. For more information, please visit the CMSC web site at: http://www.mscare.org.

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